1878.] of Astronomical Tables. 151 



Table IV. gives the mean motions already named for each 

 year in a century. 



Table V. gives the same motions 



(a) for the period of 61 years, 1500 to 1560 A.D. 



(6) for 1561 to 1621 ... 



(c) for 1622 to 1682 ... 



{d) for 1683 to 1743-.. . 



\e) for of 57 years, 1744 to 1800 ... 



Table VI. gives the same motions enumerated in the last 

 Table for every day in the year. 



Table VII. gives them, to the 12,960,000*^^ part of a second of 

 arc, marked thus """, for hours and minutes of a day. 



Table VIII. gives the Prosthaphseresis of the Equinoxes, and 

 of the " eighth sphere." 



Table IX. gives that of the Centre of the Sun. 



Table X. gives that of the Sun's orbit. 



Tables XL XII. give the Prosthaphseresis for the Centre and 

 the Orbit of the Moon. 



Tables XIII. to XXII. give it for the Centres and Orbits of the 

 Five Planets. 



Table XXIII. seems designed for comparing the results of the 

 last Tables. 



Tables XXIV. to XXX. give the true daily motion of the Sun, 

 Moon, and Planets. 



Table XXXI. gives the Latitude of the Planets: the part 

 referring to Mercury is much the longest, while that referring to 

 Saturn only occupies thirty lines : the rest in proportion. 



Table XXXII. gives the Latitude of the Moon throughout its 

 Orbit. 



Table XXXIII. shows how to compute the relative situations 

 of the Planets. 



Tables XXXIV., XXXV. show how to compute the situation 

 of the Moon towards the Planets, and vice versa. 



The Tables are calculated to a considerable degree of minute- 

 ness ; including frequently the 3600*^ part of a second of arc 

 (marked thus — "") as will be seen under Table I. : and in one case, 

 viz. Table VII., I have noticed the 3600*^ part of this fraction ; on 

 the modern system these units would be expressed by 0".000277 &c. 

 and 0".0000000771 respectively. An expert in the handwriting 

 of the period might in this way approximately determine the date 

 of the volume; but it is also possible that it might be inferred 

 from the use of two expressions, which indicate the time of its 

 compilation: they are the employment of the phrase "Caput 

 Draconis " to mean the Moon's ascending node : and the occur- 

 rence of the expression " eighth sphere" (in Latin sometimes 

 " octava splicera" sometimes " octavus orbis") to indicate the 



